I use a Canon FS100. It's worked great for a long time, quality is much better than most in car videos I watch. It recently stopped holding a charge though, battery wasn't the culprit. It's at Canon and I believe they'll fix it at no cost for me other than shipping it there. The one thing that sucks about it is it records in .mod which seems to be rare, because I can't find any decent software to edit with.

Here's some of my in car footage:
http://www.youtube.com/watch?v=lBxu8...eature=channel